Most of the counties in South Texas, Hawaii, NYC area, Bay Area, Los Angeles/OC, Atlanta area, and perhaps Cook County, IL (Chicago) have high mixed race populations. The big major cities, or areas where two races have historically interacted (which is in the case for S. Texas and Hawaii) will have a lot of mixed race populations.

This data is available on the Census website if you're willing to look for it. lol.

And Census released the USA County database files fairly recently. They are here.

Assuming I have the right column (RHI605210D), the county with the highest percentage of people of two or more races is Hawaii County, Hawaii, a.k.a. the Big Island, at 29.5%. The top ten counties are dominated by counties or equivalents from Hawaii and Alaska, with one county from Oklahoma on the list:

That's all 5 Hawaiian counties, 4 Alaskan boroughs/CDPs and a county from Oklahoma. The only county from outside of those 3 states in the top 20 is Mahnomen, MN at number 20.

Yellowstone National Park, MT, Clifton Forge, VA and South Boston, VA have no persons of two or more races. In fact, it looks like they have no people at all. Of those counties with residents, Billings, ND and Hayes, NE are last with 0.1% of the population of two or more races.

It would be interesting to see the county with the highest white-black mixed race %.

I would say the counties along the "Black Belt" from Mississippi to North Carolina would have highest rates of black-white mix.

Doubt it. Mississippi has one of the lowest percentages of mixed-race people, and there's still widespread disapproval of black-white dating and marriage throughout much of the South. Things have changed a lot in the last 40 years, but they haven't changed that much.

The racial data is all self-reported. The whole definition of racial identity is far from 100% objective for people of mixed ancestry. And plenty of people don't know their background. Nearly every black person has white ancestry if you go far enough back to get to the days of slave rape. And there's a fair amount of Native American descent floating around the gene pool too. There's no real way to answer this question.

This data is available on the Census website if you're willing to look for it. lol.

And Census released the USA County database files fairly recently. They are here.

Assuming I have the right column (RHI605210D), the county with the highest percentage of people of two or more races is Hawaii County, Hawaii, a.k.a. the Big Island, at 29.5%. The top ten counties are dominated by counties or equivalents from Hawaii and Alaska, with one county from Oklahoma on the list:

That's all 5 Hawaiian counties, 4 Alaskan boroughs/CDPs and a county from Oklahoma. The only county from outside of those 3 states in the top 20 is Mahnomen, MN at number 20.

Yellowstone National Park, MT, Clifton Forge, VA and South Boston, VA have no persons of two or more races. In fact, it looks like they have no people at all. Of those counties with residents, Billings, ND and Hayes, NE are last with 0.1% of the population of two or more races.

Hawaiian Islander and Alaskan Native might be checked by some people from Hawaii or Alaska, just like many District of Columbia residents believe they were born in Washington.

The answer to this question is probably impossible to determine; self-reporting measures such as the U.S. Census generally tend to greatly underestimate actual multiracial population. For example, genetic testing indicates that 20% of African Americans are at least a quarter European, and that the average African American has around 20% European ancestry. Similar studies reveal that ~30% of white Americans have detectable African ancestry (relatedly, this controversial paper published in 1958 analyzed population trends in past census records to estimate that 21% of white Americans living at the time had black ancestry). Also, most Hispanic/Latino Americans have some degree of both European and Amerindian ancestry (and maybe African or some Asian blood as well), even though many Hispanics with mixed heritage still self-identify as white on the Census. To really answer this question you'd have to determine what proportion of mixed racial ancestry would be required for one to be "multiracial", then use studies and census results to estimate an answer.

My guess though would be Maverick County, Texas (95.7% Hispanic, equal to a few other Texas border counties, but much of the non-Hispanic population in Maverick Co. is the Kickapoo Indian Tribe which only requires 1/4 tribal blood for membership).

However, this all ignores the fact that race is really just a social construct and is thus entirely arbitrary. "Mestizo" might as well be a race, given the hundreds of years it has had to develop, and similarly "African American" should probably be considered a discrete racial group as well. With race being a completely subjective category, what is considered "multiracial" is entirely subjective as well.

It would be interesting to see the county with the highest white-black mixed race %.

I would say the counties along the "Black Belt" from Mississippi to North Carolina would have highest rates of black-white mix.

Doubt it. Mississippi has one of the lowest percentages of mixed-race people, and there's still widespread disapproval of black-white dating and marriage throughout much of the South. Things have changed a lot in the last 40 years, but they haven't changed that much.

Exactly. Of the top 50 counties with the highest percentages of mixed-race people, less than half (24) even are over 1% black.

Logged

"George Bush supports abstinence. Lucky Laura."- sign seen at the March for Women's Lives, 4/25/04